source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootInfo.asm@ 97

Last change on this file since 97 was 88, checked in by Tomi Tilli, 14 years ago

Changes to XTIDE Universal BIOS:

  • Now uses new libraries (untested)
  • Non-working since code size is too large
File size: 5.4 KB
Line 
1; File name : BootInfo.asm
2; Project name : XTIDE Universal BIOS
3; Description : Functions for generating and accessing drive
4; information to be displayed on boot menu.
5
6; Section containing code
7SECTION .text
8
9;--------------------------------------------------------------------
10; Creates new BOOTNFO struct for detected hard disk.
11;
12; BootInfo_CreateForHardDisk
13; Parameters:
14; DL: Drive number
15; DS:DI: Ptr to Disk Parameter Table
16; ES:SI: Ptr to 512-byte ATA information read from the drive
17; Returns:
18; ES:BX: Ptr to BOOTNFO (if successful)
19; CF: Cleared if BOOTNFO created succesfully
20; Set if any error
21; Corrupts registers:
22; AX, BX, CX, DX
23;--------------------------------------------------------------------
24ALIGN JUMP_ALIGN
25BootInfo_CreateForHardDisk:
26 call BootInfo_GetOffsetToBX ; ES:BX now points to new BOOTNFO
27 call BootInfo_StoreSectorCount
28 jmp SHORT BootInfo_StoreDriveName
29
30
31;--------------------------------------------------------------------
32; Returns offset to BOOTNFO for wanted drive.
33;
34; BootInfo_GetOffsetToBX
35; Parameters:
36; DL: Drive number
37; DS: RAMVARS segment
38; Returns:
39; BX: Offset to BOOTNFO struct
40; Corrupts registers:
41; AX
42;--------------------------------------------------------------------
43ALIGN JUMP_ALIGN
44BootInfo_GetOffsetToBX:
45 mov bl, dl ; Copy drive number to BL
46 mov al, BOOTNFO_size ; Size of struct
47 sub bl, [RAMVARS.bFirstDrv] ; Drive number to index
48 mul bl ; AX = Offset inside BOOTNFO array
49 add ax, BOOTVARS.rgBootNfo ; Add offset to BOOTNFO array
50 xchg bx, ax ; Copy result to BX
51 ret
52
53
54;--------------------------------------------------------------------
55; Stores total sector count to BOOTNFO.
56;
57; BootInfo_StoreSectorCount
58; Parameters:
59; ES:BX: Ptr to BOOTNFO
60; ES:SI: Ptr to 512-byte ATA information read from the drive
61; DS:DI: Ptr to Disk Parameter Table
62; Returns:
63; CF: Cleared if variables stored succesfully
64; Set if any error
65; Corrupts registers:
66; AX, CX, DX
67;--------------------------------------------------------------------
68ALIGN JUMP_ALIGN
69BootInfo_StoreSectorCount:
70 push bx
71 call AtaID_GetTotalSectorCount ; Get to BX:DX:AX
72 mov cx, bx ; Now in CX:DX:AX
73 pop bx
74 mov [es:bx+BOOTNFO.twSectCnt], ax
75 mov [es:bx+BOOTNFO.twSectCnt+2], dx
76 mov [es:bx+BOOTNFO.twSectCnt+4], cx
77 clc
78 ret
79
80
81;--------------------------------------------------------------------
82; Stores drive name to BOOTNFO.
83;
84; BootInfo_StoreDriveName
85; Parameters:
86; ES:BX: Ptr to BOOTNFO
87; ES:SI: Ptr to 512-byte ATA information read from the drive
88; DS:DI: Ptr to Disk Parameter Table
89; Returns:
90; CF: Cleared if variables stored succesfully
91; Set if any error
92; Corrupts registers:
93; AX, CX
94;--------------------------------------------------------------------
95ALIGN JUMP_ALIGN
96BootInfo_StoreDriveName:
97 push ds
98 push si
99 push di
100
101 ; DS:SI to ATA source string
102 push es
103 pop ds
104 add si, BYTE ATA1.strModel
105
106 ; ES:DI to BOOTNFO destination string
107 lea di, [bx+BOOTNFO.szDrvName]
108
109 ; Read string
110 mov cx, LEN_BOOTNFO_DRV>>1
111 call BootInfo_StoreAtaString
112 pop di
113 pop si
114 pop ds
115 clc
116 ret
117
118;--------------------------------------------------------------------
119; Stores ATA string.
120; Byte ordering will be corrected and string will be STOP terminated.
121;
122; BootInfo_StoreAtaString
123; Parameters:
124; CX: Maximum number of WORDs to copy (without STOP)
125; DS:SI: Ptr to ATA string
126; ES:DI: Ptr to destination string
127; Returns:
128; Nothing
129; Corrupts registers:
130; AX, CX, SI, DI
131;--------------------------------------------------------------------
132ALIGN JUMP_ALIGN
133BootInfo_StoreAtaString:
134 lodsw ; Load WORD from DS:SI to AX
135 xchg al, ah ; Change byte order
136 call BootInfo_StoreAtaChar
137 jc SHORT .Return ; Return if invalid character
138 mov al, ah ; Write next char
139 call BootInfo_StoreAtaChar
140 jc SHORT .Return ; Return if invalid character
141 loop BootInfo_StoreAtaString ; Loop while words left
142.Return:
143 xor ax, ax ; Terminate string with NULL
144 stosb
145 ret
146
147;--------------------------------------------------------------------
148; Stores ATA character.
149;
150; BootInfo_StoreAtaChar
151; Parameters:
152; AL: Character to store
153; ES:DI: Ptr to destination character
154; Returns:
155; DI: Incremented to next character
156; CF: Set if non writable ASCII character
157; Corrupts registers:
158; Nothing
159;--------------------------------------------------------------------
160ALIGN JUMP_ALIGN
161BootInfo_StoreAtaChar:
162 cmp al, 20h ; First allowed ASCII char?
163 jb SHORT .SkipStoring ; If below, end string
164 cmp al, 7Eh ; Last allowed ASCII char?
165 ja SHORT .SkipStoring ; If above, end string
166 stosb ; Store character
167 clc ; Clear CF to continue with next char
168 ret
169.SkipStoring:
170 stc
171 ret
172
173
174;--------------------------------------------------------------------
175; Finds BOOTNFO for drive and return total sector count.
176;
177; BootInfo_GetTotalSectorCount
178; Parameters:
179; DL: Drive number
180; DS: RAMVARS segment
181; Returns:
182; BX:DX:AX: 48-bit sector count
183; Corrupts registers:
184; Nothing
185;--------------------------------------------------------------------
186ALIGN JUMP_ALIGN
187BootInfo_GetTotalSectorCount:
188 push ds
189 call BootInfo_GetOffsetToBX
190 LOAD_BDA_SEGMENT_TO ds, ax
191 mov ax, [bx+BOOTNFO.twSectCnt]
192 mov dx, [bx+BOOTNFO.twSectCnt+2]
193 mov bx, [bx+BOOTNFO.twSectCnt+4]
194 pop ds
195 ret
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